On manipulating memories, we're not as far behind Hollywood as you might think

Deep brain stimulation is racing ahead, and the ethical issues associated with it are starting to be debated.

Jack Nicholson in the film version of "One Flew Over the Cuckoo's Nest".

Remember Total Recall? When the film came out in 1990, its premise, in which people take virtual holidays using memory manipulation, seemed farfetched. But on 20 August President Obama’s commission on bioethics debated what we ought to do about memory manipulation. That’s because it is just one of many invasive actions we are beginning to perform on the brain.

This month, the first trials of a new technique for controlling Parkinson’s disease began. A German sufferer has had a “deep brain stimulation” device, essentially a pair of electrodes, implanted in his brain. It will monitor the brain’s activity to deliver electrical currents designed to combat tremors and muscle rigidity. A similar technique has been shown, in a few cases, to reverse the shrinkage of brain tissues associated with Alzheimer’s disease. This reversal was not only about the neural tissue’s physical appearance: it led to improved brain functioning. No one knows how it works; the best guess is that it stimulates the growth of neurons.

Deep brain stimulation is also a treatment option if you have obsessive compulsive disorder. OCD appears to arise when electrical circuits conveying signals between the emotional and the decision-making parts of the brain become stuck in feedback loops. That leads to people compulsively repeating actions because the anxieties associated with not having done the task don’t get erased. A jolt of electricity seems to clear the brain jam, however. Similar treatments seem to be a cure for depression in some people.

And, true to Hollywood, we are now manipulating memories. We’re not yet at the virtual holiday stage, but mice are starting to have some strange experiences. Last month it was reported that electricity delivered to a mouse’s hippocampus gave it a memory of receiving a shock to the foot.

Hence the need for ethical review: it is easy to see how this could eventually be used to create a tool for controlling errant prisoners, say, or mental-health patients. Perhaps you remember the electroconvulsive “therapy” punishment in One Flew Over the Cuckoo’s Nest? It’s still seen as a treatment option for depression but some think it’s too blunt an instrument. Deep brain stimulation is far less blunt – yet who decides just how blunt is acceptable?

There are many other issues to face. As we begin our assault on the brain, we will begin to gather information that might turn out to be problematic. Brain experiments are already suggesting that some people have naturally poor control over impulsive actions, and are more prone to criminal or antisocial behaviour. It is important that such information should not get thrown casually into the public sphere.

For all the appropriate caution, let’s acknowledge that some of the things we’re learning to do to the brain are really rather exciting. Having a virtual holiday might sound like a bore, but what about having razor-sharp focus at the flick of a switch? The US military is piloting a scheme that is mind-bendingly futuristic: a DC electrical current applied to the brain that in effect puts you into a high-concentration zone. With “transcranial direct current stimulation”, learning is accelerated and performance in tasks that require mental focus is significantly enhanced.

The Americans are using it to improve sniper training but that won’t be the only application. One day soon you might unplug yourself and utter the immortal words: “I know kung fu.” Hollywood races ahead, but we’re not as far behind as you might think.

Michael Brooks holds a PhD in quantum physics. He writes a weekly science column for the New Statesman, and his most recent book is At The Edge of Uncertainty: 11 Discoveries Taking Science By Surprise.